Fluctuations in the diffuse X-ray background observed with Ginga
Abstract
We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log N - log S relation in the 2-10 keV energy band to a form close to the Euclidean prediction over the flux range 1E-10 - 5E-13 erg/cm2/s. The normalisation of the 2-10 keV source counts is a factor 2-3 above that derived in the softer 0.3-3.5 keV band from the Einstein Extended Medium Sensitivity Survey if a spectral conversion is assumed which ignores X-ray absorption intrinsic to the sources. Both this result and the spectral characteristics of the spatial fluctuations are consistent with relatively low-luminosity active galaxies (i.e. L_X < 1E44 erg/s) dominating the 2-10 keV source counts at intermediate flux levels. We also use the `excess variance' of the fluctuations to constrain possible clustering of the underlying discrete sources.
Cite
@article{arxiv.astro-ph/9707135,
title = {Fluctuations in the diffuse X-ray background observed with Ginga},
author = {J. A. Butcher and G. C. Stewart and R. S. Warwick and A. C. Fabian and F. J. Carrera and X. Barcons and K. Hayashida and H. Inoue and T. Kii},
journal= {arXiv preprint arXiv:astro-ph/9707135},
year = {2015}
}
Comments
16 pages, LateX and 9 jpeg figures. Accepted in MNRAS. Also at http://www.ifca.unican.es/~barcons/preprints.html